Also, you should tell on what gamemode that amount is (guessing Survival, but it's better to say it anyway), for which gamemode you want a rank and whether it's a rank or a rankupgrade.
Otherwise, people will say:
"I'll give you a rank of 10€, you give me 50K survival money". Then you get a rank in factions (or another gamemode you didn't want a rank for) and then you'll still have to pay the other player 50K or you're the one scamming.